At Focus on the Family, we've offered a range of resources and expert advice bringing biblical principles to bear in this area.Joshua Harris, for instance, has promoted a model of courtship that harkens back to a model used broadly before modern dating evolved.People attempting to follow a courtship model within today's culture, however, often run into a lot of practical questions, such as, "What if her dad is unavailable or uninterested in being involved?See which movies took sibling relationships to an unhealthy level below.That's a mess, we have different types of intimacy with people and brotherhood isn't a sexual relation, it would be very unhealthy for both. Full brothers and sisters can technically date, fall in romantic/sexual love, and bear healthy children.